Incorporation of 5-Substituted Uracil Derivatives Into Nucleic Acids. Part IV. The Synthesis of 5-Ethynyluracil

Abstract

5-Acetyluracil (I) has been treated with POCI3 to give 5-(l-chlorovinyl)-2, 4-dichloropyrimidine (II). Treatment of II with KOEt gave a mixture of 2-ethoxy-5- ethynyl-4 (3H)-pyrimidinone (MIA) and 4-ethoxy-5-ethynyl-2 (1H)-pyrimidinone (1MB). IMA and 1MB were isolated and characterised. The mixture of MIA and 1MB upon treatment with HCI gave 5(l-chlorovinyl)uracil (IV). Reaction of IV with KOEt gave 5-ethynyluracil (V). 5-Ethynyluracil was more easily obtained by the treatment of II with KOH in aqueous dioxan. © Information Retrieval Limited.